Navigation for a robotic work tool

Abstract

A robotic work tool system (200) comprising a robotic work tool (100) comprising a controller (110), the controller (110) being configured to determine an area locality (310) associated with a hindrance; determine a classifier (C) associated with the area locality (310); and determine an action for the robotic work tool (100), wherein the action is based on the classifier (C).

The invention claimed is: 
     
         1 . A robotic work tool system comprising a robotic work tool comprising a controller, the controller being configured to:
 determine an area locality associated with a hindrance;   determine angles at which the robotic work tool approaches the area locality;   determine a classifier associated with the area locality;   determine an action for the robotic work tool; and   control the robotic work tool to perform the action,   wherein the action is based on the classifier,   wherein the angles at which the robotic work tool approaches the area locality corresponds to one out of a plurality of angle sectors and to an arrival angle of the robotic work tool, and   wherein the classifier is based on both the one out of the plurality of angle sectors and the arrival angle.   
     
     
         2 . The robotic work tool system according to  claim 1 , wherein the classifier is associated with a nature of an effect of the area locality. 
     
     
         3 . The robotic work tool system according to  claim 1 , wherein the controller is further configured to:
 detect the hindrance;   determine the area locality;   associate the hindrance with the area locality; and   determine the classifier based on a type of hindrance and store the classifier.   
     
     
         4 . The robotic work tool system according to  claim 3 , wherein the type of hindrance is at least one of gradient, slip, obstacle, or stuck. 
     
     
         5 . The robotic work tool system according to  claim 1 , wherein the controller is further configured to determine the classifier based on a retrieval of a stored classifier. 
     
     
         6 . The robotic work tool system according to  claim 1 , wherein the controller is further configured to:
 increase a counter associated with the area locality;   determine whether the counter exceeds a classifier threshold associated with a hindrance type and a corresponding classifier, and, if so, determine the corresponding classifier to be a classifier associated with the classifier threshold.   
     
     
         7 . The robotic work tool system according to  claim 1 , wherein the robotic work tool further comprises a memory and wherein the controller is further configured to store at least one indication of the area locality and associated classifier in a virtual map in the memory. 
     
     
         8 . The robotic work tool system according to  claim 7 , wherein the controller is further configured to operate the robotic work tool within a work area and to store a plurality of indications of area locality and associated classifier, wherein the stored area localities are adjacent one another and covers at least a portion of the work area. 
     
     
         9 . The robotic work tool system according to  claim 7 , wherein the controller is further configured to retrieve at least one area locality from the memory and adapt the navigation of the robotic work tool based on the location of the area locality and/or the classifier of the area locality. 
     
     
         10 . The robotic work tool system according to  claim 1 , wherein the controller is further configured to determine the area locality based on a determination of the location of the robotic work tool. 
     
     
         11 . The robotic work tool system according to  claim 1 , wherein the action is at least one of: adapting speed of approach, avoiding area locality, entering in reverse, approaching at an approach angle, stopping work tool, limit acceleration, limiting turn angle, or adapting operating height of work tool. 
     
     
         12 . The robotic work tool system according to  claim 1 , wherein the robotic work tool is a robotic lawnmower. 
     
     
         13 . A method for use in a robotic work tool system comprising a robotic work tool, the method comprising:
 determining an area locality associated with a hindrance;   determining angles at which the robotic work tool approaches the area locality;   determining a classifier; and   determining an action for the robotic work tool; and   control the robotic work tool to perform the action,   wherein the action depends on the classifier,   wherein the angles at which the robotic work tool approaches the area locality corresponds to one out of a plurality of angle sectors and to an arrival angle of the robotic work tool, and   wherein the classifier is based on both the one out of the plurality of angle sectors and the arrival angle.